Nuclear Data Sheets for A = 231

Spectroscopic data for all nuclei with mass number A=231 have been evaluated, and the corresponding level schemes from radioactive decay and reaction studies are presented.Highlights of this evaluation include:A new interpretation of γ–ray spectroscopic results measured with the GAMMASPHERE spectrometer (2002AbZV, 2000JaZY, 1999Br17) has established the level structure of the ground state rotational band 1/2[400] up to spin/parity 45/2+ in 231Ac.Precise measurements of energies and cross sections of scattered tritons from the 232Th(d,t) reaction has produced or confirmed the identification of several rotational bands in 231Th.The alpha hindrance factors (HF) presented in this evaluation were calculated using values of the radius parameter (r0) interpolated from those for even–even adjacent nuclei given in 1998Ak04.The Limitation of Relative Statistical Weight (LWM) method (1985ZiZY) has been used for discrepant data throughout this evaluation.